About 85% of mankind's current energy needs are met by fossil fuels. Green energy companies have gained momentum in recent years which has fueled interest in the use of alternative energies. While there is some resistance to biofuel development and production from some policy makers, the pursuit of alternative energy sources is only likely to intensify. This is primarily due to growing global concerns of pollution and greenhouse effects of petroleum-based energy. In addition, price instability caused by rising worldwide demand is likely to impact future world energy markets.
Further, there is growing recognition that petroleum is a finite resource. As the imbalance between supply and demand for petroleum-based energy continues to increase, prices will rise and consumers will demand alternatives. For these reasons, even large oil companies have invested in the biofuel market. Billions of dollars are already tied to the biofuel and alternative energy markets, and these will continue to grow at a faster pace than petroleum-based energy markets over the next decade.
Currently, the most common biofuel alternative to fossil fuels is produced by fermentation of edible crops, mainly sugarcane and corn. However, biofuel production from these sources has created widespread debate, as it displaces land needed for food production. The challenge remains to develop renewable energy industries which are operatively sustainable and cost-competitive with existing energy options.
Fresh water is required for various agricultural and human needs and its supply is limited. On the contrary, sea water is abundantly available and generating fuel from brackish water is a viable alternate to solve the energy crisis. Brackish water found in ocean bays and gulfs also provides an enormous opportunity. Furthermore, in winter, de-icing salts, mainly in the form of sodium chloride get washed downstream resulting in salting of streams and waterways. The salty runoff water could be used as a source for generating biofuel. With nearly three quarters of the earth's surface covered by oceans, finding ways to better utilize salt water is critical to sustaining humanity.
The use of photosynthetic algae and cyanobacteria (blue-green algae) has recently received widespread attention for significant biofuel production due to their rapid growth, lack of requirement for arable land, CO2 fixation, and genetic tractability (journal.frontiersin.org/article/10.3389/fbioe.2013.00007/full). These organisms can inhabit a wide-range of environmental conditions and have evolved different mechanisms to sustain their photosynthesis.
In particular, F. diplosiphon has a light-dependent acclimation process known as complementary chromatic adaptation which gives it the flexibility to grow in varying light intensities. These organisms grow in aquatic ecosystems which allow the use of CO2 at higher concentrations than that of ambient air and could potentially allow the use of concentrated CO2 emissions from waste industrial sources. Standard oil yields from cyanobacteria/algae range from 1,000-6,500 gallons/acre/year. (Hannon, M. et al., “Biofuels from algae: challenges and potential,” Biofuels, 1, 763-784 (2010); and International Energy Outlook. U.S. Energy Information Administration. 284 (2009)).
The Department of Energy estimates that oil yields from cyanobacteria/algae range from 1,000-6,500 gallons/acre/year (National Algal Biofuels Technology Roadmap. U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Biomass Program, (2010)). Calculation and analysis of oil from lipids by Weyer and his team (Weyer, K. M. et al., “Theoretical maximum algal oil production,” Bio Energy Research, 3, 204-213 (2009)) has estimated a theoretical yield of 38,000 gallons/acre/year and a current practical yield of 4,350-5,700 gallons/acre/year from cyanobacteria/algae.
Cyanobacteria convert light energy into chemical energy through photosynthesis. To inhabit a wide range of environmental conditions, these organisms have evolved different mechanisms to sustain their photosynthesis (Gutu, A. et al., “Emerging perspectives on the mechanisms, regulation, and distribution of light color acclimation in cyanobacteria,” Molecular Plant, 5, 1-13 (2012); Montgomery, B. L., “Shedding new light on the regulation of complementary chromatic adaptation,” Central European Journal of Biology, 3, 351-358(2008)).
Over $6 trillion is spent worldwide on energy, and even a small shift toward biofuel represents billions of dollars in this enormous market.